1. Field of the Invention
The present invention generally relates to engineering and geographical information systems for the design and management of communications networks, and, more particularly, to a method for creating, using, and managing a three-dimensional (3-D) representation of the physical environment comprised of both terrain and building data.
2. Background Description
As wireless communications use increases, radio frequency (RF) coverage within and around buildings and signal penetration into buildings from outside transmitting sources has quickly become an important design issue for wireless engineers who must design and deploy cellular telephone systems, paging systems, or new wireless systems and technologies such as personal communication networks or wireless local area networks. Designers are frequently requested to determine if a radio transceiver location, or base station cell site can provide reliable service throughout an entire city, an office building, arena or campus. A common problem for wireless systems is inadequate coverage, or a “dead zone,” in a specific location, such as a conference room. It is now understood that an indoor wireless PBX (private branch exchange) system or wireless local area network can be rendered useless by interference from nearby, similar systems. The costs of in-building and microcell devices which provide wireless coverage within a 2 kilometer radius are diminishing, and the workload for RF engineers and technicians to install these on-premises systems is increasing sharply. Rapid engineering design and deployment methods for microcell and in-building wireless systems are vital for cost-efficient build-out.
Analyzing radio signal coverage penetration and interference is of critical importance for a number of reasons. A design engineer must determine if an existing outdoor large-scale wireless system, or macrocell, will provide sufficient coverage throughout a building, or group of buildings (i.e., a campus). Alternatively, wireless engineers must determine whether local area coverage will be adequately supplemented by other existing macrocells, or whether indoor wireless transceivers, or pieocells, must be added. The placement of these cells is critical from both a cost and performance standpoint. If an indoor wireless system is being planned that interferes with signals from an outdoor macrocell, the design engineer must predict how much interference can be expected and where it will manifest itself within the building, or group of buildings. Also, providing a wireless system that minimizes equipment infrastructure cost as well as installation cost is of significant economic importance. In addition, after a system or network is installed, there is continued need to manage the installed network over time and space, to record and continually edit and modify the maintenance records of the system as well as track the cost, maintenance repairs, and ongoing performance of the system and the components that make up the system, so that on-going operational data may be gathered, understood, aggregated and used for further build-out of systems. As in-building and microcell wireless systems proliferate, these issues must be resolved quickly, easily, and inexpensively, in a systematic, standardized, and repeatable manner.
There are many computer aided design (CAD) products on the market that can be used to design the environment used in one's place of business or campus. AutoCAD and AutoCAD Map from Autodesk, Inc., MapInfo from MapInfo, Inc., ArcView from ArcInfo, and Smallworld from General Electric are examples of powerful CAD and geographic information system (GIS) software packages designed to model and represent physical environments. However, none of the preceding tools provide an automated means of generating a seamlessly integrated, three-dimensional digital representation of a physical environment that combines terrain, buildings, and the internal structure of the buildings. Similarly, WiSE from Lucent Technology, Inc., SignalPro from EDX, PLAnet by Mobile Systems International, Inc. (now Marconi Ltd.), Celplan tom Celplan Technologies, Inc, Wizard by Agilent Technologies, Asset by Aircom, and TEMS and TEMS Light from Ericsson are examples of wireless CAD products used to assist wireless engineers in the design and deployment of wireless communication systems.
In practice, however, many pre-existing building or campus databases are designed only on paper, or are represented as photographs or bitmap images, as a database of parameters defining the environment does not readily exist. Only recently has it been possible to acquire very accurate data regarding the physical characteristics of terrain along with detailed information on building positions and geometry. It has been difficult, if not generally impossible, to gather this disparate information and manipulate the data for the purposes of planning and implementation of indoor and outdoor RF wireless communication systems, and each new environment requires tedious manual data formatting in order to run with computer generated wireless prediction models.
Illustrative of the state of the art in the creation of accurate, efficient three-dimensional digital models of terrain and buildings for the purpose of site-specific propagation modeling or system design are several patents directed at related subject matter to the present invention. These include U.S. Pat. No. 5,491,644 to Pickering et al., U.S. Pat. No. 5,561,841 to Markus, U.S. Pat. No. 5,987,328 to Ephremides and Stamatelos, U.S. Pat. No. 5,794,128 to Brockel, et al., U.S. Pat. No. 6,111,857 to Soliman et al., U.S. Pat. No. 5,625,827 to Krause, et. al., U.S. Pat. No. 5,949,988 to Feisullin et al., U.S. Pat. No. 5,598,532 to Liron, U.S. Pat. No. 5,953,669 to Stratis et. al. and U.S. Pat. No. 6,044,273 to Tekinay. The above listed patents teach various methods and systems for the simulation of wireless communication systems utilizing, in some fashion, information regarding the physical environment in which the communication systems are positioned. They do not, however, teach any type of asset management which combines site-specific environment models with models of the actual installed equipment infrastructure, nor do they provide any information as to the specific format of the digital model of the physical environment or any indication of how the digital model was constructed.
Other patents that deal with asset management and which allow the current invention include U.S. Pat. No. 6,047,321 to Raab, U.S. Pat. No. 6,058,397 to Barrus, et. al., U.S. Pat, No. 6,067,030 to Burnett, et al., U.S. Pat. No, 6,223,137 to McKay, U.S. Pat. No. 5,523,747 to Wise, and U.S. Pat. No. 6,006,171 to Vines. A survey of the state-of-the-art in the use of maps and geographic information for telecommunications asset management can be found in “GIS in Telecommunications” published in May 2001 by ESRI Press of Redlands, Calif. None of the above-referenced patents or publications contemplates the systematic creation or display, through the use of a set of rules or algorithms, of a three-dimensional digital model of the physical environment that may include outdoor environments, indoor environments, and underground environments in a seamless fashion. Furthermore, none of the above cited references contemplate combining three-dimensional digital models of internal building structures with three-dimensional models of outdoor terrain and building geometries into a database format that also includes site-specific component layout information of an actual physical distributed network.
Furthermore, the above cited references do not teach an asset management method or system that allows a site-specific database model to include a site-specific representation of a distributed network of components, such that the actual physical network of components being modeled may also be accounted for, maintained, monitored for performance or alarms, and subsequently managed in an interactive manner on a component-by-component basis or system wide basis using a common database format. While the above cited patents show the difficulty in obtaining such models for city environments, they do not suggest a systematic, repeatable and fast methodology or algorithmic approach for creating a three-dimensional model of a physical environment that combines both terrain and buildings (or other objects such as trees, natural or man made objects, towers, partitions, walls, and the like) such that the completed representation may be stored and viewed in a vector format that is optimal for the purposes of planning and deploying and tracking maintenance and cost records as well as on-going performance data of wireless communication equipment, computer network equipment, or any form of structured cabling network, or distributed network of components within a model that represents the actual physical environment.